The present invention relates generally to apparatus for placing bands on containers and more particularly to a band guiding and forming assembly for such an apparatus, for receiving flattened plastic tubing material, opening it up and smoothing out the crease lines while guiding it along a predetermined path in the apparatus towards a cutting assembly for cutting the tubing into predetermined lengths and a device for guiding the cut lengths of tubing onto the necks of containers.
In U.S. Pat. No. 3,802,152 of Strub, a banding apparatus is described. The apparatus includes a forming apparatus for opening out a flattened banding sleeve and flattening the edge creases, in which the sleeve is passed over a ball, and a pair of pinch rollers having concavities are urged against the ball on opposite sides of the sleeve so that the pinched or creased edges of the sleeve are substantially pressed out as they pass between the ball and the rollers. One problem with this apparatus is that unless the crease lines are precisely positioned between the pinch rollers and ball, the desired smoothing out of the crease lines is not achieved. The tubing has a tendency to twist, resulting in the tubing still having a crease line when it passes to the cutting station, so that it will tend to close up after cutting. This makes it more difficult to position the cut bands around the neck of a container. Another disadvantage to this technique is that it is only appropriate for one size of tubing and is not easily adjustable for different diameter tubing, as may be needed where the same banding apparatus is used for banding various different size containers.